Hi @premolar
You are using OJS 3.0.2, right?
It seems that you need the TAR command/executable on your server and/or you would have to enter the correct path to it in your OJS file config.inc.php https://github.com/pkp/ojs/blob/master/config.TEMPLATE.inc.php#L436. – It is needed for the plugin package to be extracted and the files copied at the correct destination.
There is one more way to install the plugin:
You can get the plugin package from here: Releases · pkp/quickSubmit · GitHub. Unpack it i.e. copy the unpacked plugin folder quickSubmit/ into the OJS folder plugins/importexport/. Then run this command from your OJS folder: php tools/upgrade.php upgrade. But please do the backup first, before executing this command!!!
Best,
Bozana